Wireless Intercom Technology Explained

There are a few main technologies used for wire free intercom systems. They are listed below..

Low Frequency Radio Technology - Excelent for medium range applications, low frequency signals travel far in open air, and are relatively free from interference. The main limitation is that low frequency signals do not penetrate walls as well as higher frequency signals.

High Frequency Microwave Technology - Usually the commonly used 2.4GHz band, these systems penetrate masonry walls extremely well, however are usually limited by regulations that govern transmission power and distance allowed; making them most suitable for short range applications.

GSM mobile phone technology - Many modern intercom systems use a mobile phone SIM card to communicate exactly like a standard mobile phone. These systems have absolutely no range limit and have advanced features such as being able to call several numbers in sequence when a visitor presses the call button. The only disadvantages are that the site needs mobile phone coverage before the system will work, and since the system uses a SIM card, charges similar to a mobile phone under light use will be incurred.

Data Over Electrical - This new technology sends voice data around the electrical wiring in a building where at the other end it is decoded from the mains circuit and turned back into voice. These systems work well over several hundred meters in rural areas. The only limitation with this technology is that for it to work, both units must be on the same phase or electrical circuit.